In the past objects such as dolls, toy cars, and cloth have been colored with a paint whose color is temperature dependent. The color of these objects has been changed by applying cold water to change a first color to a second color and hot water to return the first color to the object. Wash cloths and sponges have been used to apply cold and hot water to the object for color change. For convenience, handles have been attached to the sponges. Also tubular members having closed ends and opposing ends equipped with metal or plastic type applicators of a desired shape have been used to hold cold and hot water for cooling or heating the applicators for use in changing the color of the paint.
Several problems attend the use of cold and hot water. For example, when wash cloths or sponges or both are used as applicators an open container is required. Using the container often results in water spills or water messes which have to be cleaned up. While, water messes are alleviated with the use of tubular type applicators, the cold and hot water therein must be frequently changed to maintain operating temperatures. In some applications, for example, toy cars, cold and hot running taps have been used for changing the color. This is objectionable as the paint is damaged by intense heat.
With respect to the use of thermoelectric devices for generating cold and hot, they include thermoelements having opposing plates, typically, one plate constitutes the cold side for cooling an object in contact therewith and a hot side which is cooled to maintain the temperature difference essential for continued device operation. When it is desired to heat the object, the polarity is changed and the cold side then becomes the hot side.
A very small, light apparatus which is easy to handle in one hand is disclosed in U.S. Pat. No. 3,971,229 issued Jul. 27, 1976 to Yves Emile Privas for an "Apparatus For Producing Cold Principally For The Application Of Cold By Contact On The Body Of Living Beings. This apparatus includes a tubular cylindrical body closed at one end by a plug. The body includes a rechargeable battery adjacent to the plug end. A switch connects the battery to a thermoelectric element mounted with its cold face projecting through an aperture of a retaining cap. The retaining cap maintains the hot face in contact with a cylindrical heat sink which extends back into the tubular body. The applicator is either the actual surface of the cold face or an auxiliary surface which is thermally connected to the cold face. In this applicator, only one plate is available for applying cold to an object. This patent also recognizes that a cold face and a hot face of a thermoelectric element can be used simultaneously for a toy which combines a refrigerator and stove hot plate toy. However, there is no teaching or suggestion that the cold applicator could be modified to provide cold and hot applicators.